// 987654321*123456789
#include <stdio.h>
main()
{
    int a[9] = {1, 2, 3, 4, 5, 6, 7, 8, 9};
    int b[9] = {9, 8, 7, 6, 5, 4, 3, 2, 1};
    int sum[20] = {0};
    int temp;
    for (int i = 0; i < 9; i++)
    {
        for (int j = 0; j < 9; j++)
        {
            sum[i + j] += a[i] * b[j];
        }
        for (int k = 0; k < 20; k++)
        {
            if (sum[k] >= 10)
            {

                temp = sum[k] / 10;
                sum[k + 1] += temp;
                sum[k] %= 10;
            }
        }
    }
    int flag = 0;
    for (int i = 20; i > 0; i--)
    {
        if (sum[i] != 0)
        {
            flag = 1;
        }
        if (flag == 1)
            printf("%d", sum[i]);
    }
    return 0;
}